Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 10)
10.
A jogger running at 9 kmph alongside a railway track in 240 metres ahead of the engine of a 120 metres long train running at 45 kmph in the same direction. In how much time will the train pass the jogger?
Answer: Option
Explanation:
Speed of train relative to jogger = (45 - 9) km/hr = 36 km/hr.
| = |  |
36 x | 5 |  m/sec |
| 18 |
= 10 m/sec.
Distance to be covered = (240 + 120) m = 360 m.
 Time taken = |
|
360 | sec |
= 36 sec. |
| 10 |
Discussion:
106 comments Page 6 of 11.
Neel said:
1 decade ago
We subtract 45-9 so as to make the position of the jogger to be the reference position. By subtracting that the jogger is stationary now.
Ankush said:
1 decade ago
5/18 we can get like that.
Suppose speed is 10 km/hr so we can say like that.
(10)*1000/3600 m/second, so 1000/3600 will become 5/18.
Suppose speed is 10 km/hr so we can say like that.
(10)*1000/3600 m/second, so 1000/3600 will become 5/18.
ABHINAND said:
8 years ago
I think the platfr0m length n0 need t0 take. The train thake 8 sec t0 pass the man. After concider the relative speed.
120/ (36*5/18).
120/ (36*5/18).
Shubhankar said:
8 years ago
Jogger is also moving, I don't think answer is correct please update we have to first come to a meeting point of train and the jogger.
Sarang said:
7 years ago
Distance= speed * time.
120+240=45-9km/h*time,
360=36km/h*time,
360=36*5/18*time,
360=2*5*time,
360=10*time,
Time=360/10,
Time=36s.
120+240=45-9km/h*time,
360=36km/h*time,
360=36*5/18*time,
360=2*5*time,
360=10*time,
Time=360/10,
Time=36s.
Viji said:
1 decade ago
Any body please explain that the relative speed calculation for both speed and distance when opposite and same direction moving ?
Mohit Tiwari said:
8 years ago
The relative speed is 10m/s. But train needs to cover 240+2*(length of train) to pass the jogger so the answer should be 48 m/s.
Kavya said:
7 years ago
Why didn't we use relative speed formula here instead why we did use the speed of train relative to jogger?
Please explain me.
Please explain me.
Shri.. said:
3 years ago
@Swetty.
Because we have to calculate the relative speed of both objects.
Train speed = 45 kmph.
Jogger speed= 9 kmph.
Because we have to calculate the relative speed of both objects.
Train speed = 45 kmph.
Jogger speed= 9 kmph.
(2)
Reddy said:
10 years ago
In this problem the question is how much time it take to cross the jogger why are you considering the plat form length?
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